As conventional containers for storing liquid, there are known, for example, aerosol containers and cosmetic containers. These containers are formed using, for example, glass, metal, or a plastic material. In addition to the above liquid, compressed gas (so-called propellant gas) is sealed into the containers. When a nozzle of the container is opened, the liquid and the compressed gas mix together and the resulting mixture is ejected as a spray.
In the case where only the liquid is to be ejected, it has been proposed to use a container of a double structure provided with a piston, etc. (see, for example, JP-63-190669). Recently, studies have been being made about a fuel cell as a small-sized power supply in a small-sized portable remote terminal such as a notebook-size personal computer of PDA (Personal Data Assistant). As means for the supply of fuel to the fuel cell it has been proposed to use a fuel container (fuel cartridge). As the fuel to be injected into the fuel container, a liquid fuel mixture of methanol and pure water, or ethanol and pure water, is being studied for example in the case where the fuel cell is DMFC.
Small-sized devices such as a notebook-size personal computer are desired not to carry thereon a fuel supply pump, a pressure regulating mechanism and a residual fuel quantity detecting mechanism due to a restriction imposed on its size. In addition, for the improvement of convenience on the user side, it is expected to develop a less expensive, small-sized and lightweight fuel container.
Further, for ejecting liquid fuel with use of a fuel container filled with the liquid fuel, it is necessary for a piston-like partition wall member to operate positively. Particularly, in the case where a portable remote terminal is provided with neither a fuel supply pump nor a pressure regulating mechanism and the discharge pressure is set as low as 0.3 MPaG (gauge pressure) or lower, the partition wall member must move positively even at such a low discharge pressure.
Generally, in order that the piston-like partition wall member can move positively, lubricating oil such as silicone oil is applied to the peripheral surface of the partition wall member to enhance the slidability of the partition wall member.